There are only two types of common rail injectors are original produced by BOSCH:solenoid and piezo.

The difference between the two injectors is the speed and precision with which they inject diesel fuel. Solenoid injectors operate at 160 microseconds, and piezo injectors operate at 100 microseconds. The two technologies are not compatible – a solenoid injector can't replace a piezo injector and vice versa.

Because of the piezo injectors,the modern common rail systems CRS3-18 (with 1,800 bar) and CRS-20 (with 2,000bar) is developed for the ideal properties of engine.For every injection systems,it is a challenge to vary fuel qualities.But with the robust piezo actuator the injectors of the CRS3-18/20 are perfectly suited. Compared with a solenoid, the power of the piezo actuator is about ten times as high which could assure the less affact from the fuel small particle cotamination.